Organic light emitting diode (OLED) displays possess many outstanding properties, including self-illumination, short response time, large viewing angles, and high color saturation, and thus are used widely in a variety of applications. OLED displays include an organic light emitting layer on the substrate, where the organic light emitting layer is sandwiched between a cathode electrode and an anode electrode. A voltage is applied to the cathode electrode and the anode electrode to cause the organic light emitting layer to illuminate.
To form the organic light emitting layer of OLED displays, an evaporation device is utilized to consecutively deposit a plurality of films on the substrate. OLED evaporation techniques heat an evaporation source that has been filled with an OLED material under a vacuum, so as to sublimate or gasify the material through a mask plate and make the material deposit on the substrate. The dashed lines in FIG. 1 show a flow direction of the OLED material. As shown in FIG. 1, for carrying out OLED evaporation, the evaporation source is located at lowest level, and the substrate 11 is disposed above the mask plate 21. The mask plate 21 includes a plurality of perforations 211 configured for the evaporation treatment. As shown in FIG. 2, a plurality of spacers 13 are disposed on the substrate 11 at outer peripheries of the layer formation areas 12. Generally, smaller gaps between the substrate 11 and the mask plate 21 is, means less influence caused by the shadowing effect. However, the spacers 13 have a certain height and the gap between the substrate 11 and the mask plate 21 cannot be reduced further. For substrate of high resolution, this makes the evaporation material diffuse to other color regions to some extent, causing color mixing.
Therefore, to solve the problems encountered by the prior art, there is a need to provide a substrate and an evaporation device used for manufacturing an organic light emitting display panel.